Various types of vehicular security systems are employed in many vehicles to protect such vehicles from theft or other criminal activity. For example, a vehicular security system may be configured to communicate with some external entity (i.e. base-station/control-center; e.g. a police or security center), for delivering notifications to the external entity when an attempt is made to break into a vehicle and/or to steal the vehicle. Some vehicular security systems also include vehicle tracking systems that are operable for tracking the vehicle in case it is stolen.
In many cases, vehicle tracking security systems rely upon a GPS system to pinpoint the location of the vehicle and utilize a communication network, such as a cellular network (e.g. GSM network), to communicate and report, to a base station of a security service provider, the identity, and position of the vehicle. Reporting the vehicle's identity and/or location is typically performed utilizing conventional cellular network protocols such as via Short Message Service (SMS) or General Packet Radio Service (GPRS) data connections. In such techniques, the reporting is performed utilizing bi-lateral communication between the service provider's base station and the vehicle.
Potential vehicle thieves attempt to overcome the operation of such vehicle tracking systems by jamming signal receiving hardware within the vehicle to prevent the vehicle from communication with the base station/control center of the security service provider and/or from detecting GPS signals indicative of the vehicle's location. For example, jamming the vehicle's receiver is in some cases achieved by employing devices that create a strong wide-band signal in the receive band. This practically blocks/jams the reception of signals from the cellular network and/or from a positioning system (such as GPS satellites) at the vehicle. Once such jamming occurs, the operation of the conventional vehicle tracking systems is disrupted because GPS systems rely on reception of satellite signals to determine the position of the vehicle, and/or because communication via cellular and/or other communication networks is generally bi-lateral, requiring both receipt and transmit operations in order to establish communication with the network (e.g. the performance of bi-lateral negotiation/handshake is needed to establish communication). Thus, in the absence/failure of the reception function at the vehicle, failure may occur in obtaining the vehicle's position and/or in establishing communication with the control center of the security service provider.
There are various known in the art techniques for identifying whether jamming is being applied to communication/positioning systems (e.g. to the receivers thereof). Some techniques for jamming detection are described for example in U.S. Pat. No. 8,319,615, U.S. patent publication No. 2004/005858, and in U.S. patent publication No. 2013/217353.
U.S. patent publication No. 2011/151791 is directed to an apparatus and method for maintaining communication between a base station and with a stolen vehicle tracking device. According to this technique, at the stolen vehicle tracking module within the vehicle, it is determined whether jamming is occurring with communications between the stolen vehicle tracking module and the base station, and a temperature is measured at the stolen vehicle tracking module. When jamming is detected, an adjustment is determined for a frequency of an oscillator of the stolen vehicle tracking module and the adjustment is based at least in part upon the temperature. The frequency of operation of an oscillator is adjusted according to the adjustment. A message is transmitted to the base station according to the adjusted frequency.
U.S. patent publication No. 2011/151827 is directed to an apparatus and a method for broadcasting the detection of RF jammer presence. The jamming of a radio frequency (RF) transmission after the vehicle is parked is detected. When the jamming is detected, an emergency message is broadcast on a first random access channel (RACH) associated with the vehicle according to a last known broadcast channel (BCH). When the jamming is detected, at least one last known neighbor serving cell from a stored data structure is determined, and the emergency message is broadcast on one or more second RACHs associated with each of the at least one last known neighbor serving cells.
U.S. Pat. No. 8,175,573 discloses an apparatus and a method for maintaining communications with a vehicle in the presence of jamming. Jamming is detected as occurring to communications associated with at least one electronic device disposed at a vehicle. Responsive to detecting the jamming, an indication is transmitted from the vehicle to a base station informing the base station that jamming is occurring. Communications are subsequently conducted between the base station and the vehicle on at least one predetermined and prearranged communication channel.